php - simpleXML script -

i'm trying make simple script has convert php array xml.. can't make work.. script works fine when array has 1 dimension , when there more dimensions nodes appended "root" node

#class     class xml {         private $root = '<response />';          function __construct($root=null){             $this->root = new simplexmlelement($root ? $root:$this->root);         }          function encode($arr, $node=null){             $node = $node ? $node:$this->root;             foreach($arr $key => $value){                 if(is_array($value)){                     $this->encode($value, $node->addchild($key));                 }                 else{                     $node->addchild($key, $value);                 }             }         }          function output(){             return $this->root->asxml();         }     }   #code      $arr = array(         'test' => 'noget',         'hmmm' => 12,         'arr' => array(             99 => 'haha',             'arr2' => array(                 ),             'dd' => '333'             )         );     print_r($arr);     require_once '../class/class.xml.php';     $xml = new xml();     $xml->encode($arr);     echo $xml->output();  #output      array     (         [test] => noget         [hmmm] => 12         [arr] => array             (                 [99] => haha                 [arr2] => array                     (                     )                  [dd] => 333             )      )     <?xml version="1.0"?>     <response><test>noget</test><hmmm>12</hmmm><arr/><99>haha</99><arr2/><dd>333</dd></response> 

you're code looks quite fine want do, however, must more check optional $node parameter in:

function encode($arr, $node=null){     $node = $node ? $node:$this->root; 

i working so:

function encode($arr, $node=null){     $node = null === $node ? $this->root : $node; 

an empty simplexml element false (see last point in converting boolean list) , add empty child it's false , added again root element.